2004-10-22 04:00:00 PDT Washington -- George W. Bush is the latest president to learn that wars tend to turn elections into referendums on the presidents who wage them and that Americans like a winner, not a president or his party's chosen successor who seem bogged down in an unwinnable conflict.

Polls show the Republican president in a close race with Democrat John Kerry heading into the Nov. 2 election in which the Iraq war remains a centerpiece issue. But those same polls indicate that voters haven't decided yet if they want to stick with Bush's strategy for the war or switch to Kerry, who in the tradition of rivals running against wartime presidents is vague about what he would do differently.

"It is evident that rally-round-the-president when the nation is at war is not especially the American tradition," added Schlesinger, a critic of Bush.

New research supports Schlesinger's contention that the U.S. military deaths in Iraq, which now have now surpassed 1,100, have cumulatively sapped Bush's popularity and put his re-election in doubt. Each 100 American deaths have cut Bush's job approval rating by 1.4 percentage points, said the paper by political scientists Richard Stoll of Rice University in Houston and Richard Eichenberg of Tufts University in Medford, Mass.

Using a statistical technique that separated out the impact of casualties from such other factors as the country's economy, the two said the war had become the determining factor for Bush's re-election.

"There's a gradual withering of support for a president when Americans are being killed," Stoll said in an interview.

"The near-time future may bring bad news to the American public about Iraq, and this may bode ill for the president's approval ratings and prospects for re-election," they wrote in their paper, which they plan to update before Nov. 2.

"I still think Bush is going to win. The war is not going well, but he is still way ahead of Kerry among the public on the national security issue.

"Even with a dubious war, it's very difficult to knock out a president on national security. Either they win or they bail out. It's real simple."

What might be different for Bush is that he continually links the war in Iraq to the war against terrorism and the need to stay strong after the Sept. 11, 2001, terrorist attacks. That broadens the Iraq issue into a national security issue.

Difficulty in translating prosecution of a war into ballot box success has been especially true for war presidents in the 60 years since President Franklin D. Roosevelt won re-election in 1944 to a fourth term over Republican Thomas E. Dewey during World War II. Even that re-election was the closest of Roosevelt's four victories.

Roosevelt's successor, Harry Truman, was brought low by the Korean War and decided not to run again in 1952 after he lost the New Hampshire primary to Sen. Estes Kefauver. While some historians say Truman had indicated as early as 1950 that he wouldn't run again, others say the fact that he waited until after the March New Hampshire primary shows he would have run again except for the Korea stalemate.

Battered by Vietnam, President Lyndon B. Johnson dropped out of the 1968 race, after almost losing the New Hampshire Democratic primary to Sen. Eugene McCarthy of Minnesota. Johnson's hand-picked successor, Vice President Hubert H. Humphrey, lost by a whisker to Richard M. Nixon. It turns out that both sides played campaign-season politics with stalled peace negotiations in Paris.

After decreasing the number of Americans in Southeast Asia from about 500, 000 to 20,000, Nixon won re-election in 1972 in a landslide, in part after announcing a peace settlement, that later collapsed, just before election day.

The 1968 and 1972 manipulations of a war for election success earned the scorn of historian Stephen Ambrose, author of a two-volume biography of Nixon.

"In both instances, administrations said or implied that peace was at hand. In each case, presidents knew the government of Vietnam had not agreed, and that North Vietnam had not agreed to accept anything less than victory."

President Bush's father lost his re-election bid in 1992, despite his success in the Persian Gulf War, in part because of a sour economy at home.

Further back in U.S. history, Abraham Lincoln won re-election in 1864 during the bloody Civil War, but historians generally thank Gen. William Tecumseh Sherman for taking Atlanta from the Confederates on Sept. 2, 1864, turning the tide in Lincoln's favor.

"Victories are good for sitting presidents. The trickle, trickle of casualties isn't very good for a sitting president," said Eric Rauchway, a historian at UC Davis.

"There's no hard and fast rule you can draw. But wars tend to suck the air out of any other part of the campaign," added Rauchway, author of "Murdering McKinley," the story of how the assassination of President William McKinley, who was easily re-elected in 1900 after winning the Spanish-American War, led to the reform presidency of his vice president, Theodore Roosevelt.

McKinley put Roosevelt, a hero of the war in Cuba, on his ticket partly to benefit from the popularity arising from the war's success.